Insulinomas are a rare group of functional neuroendocrine tumours of the pancreas. Most insulinomas are benign and they grow exclusively at their origin within the pancreas, but a minority metastasizes to distant organs, mainly the liver. Insulinomas are characterised by severe hypoglycaemia induced by inappropriately increased circulating plasma insulin levels. Hypoglycaemia may be life threatening in inoperable malignant insulinomas, where there is no consensus for successful treatment.

Here, we describe the case of a 56-year-old woman, diagnosed with a metastatic insulinoma (neuroendocrine grade II, Ki67 at 4%) to the liver who had been treated initially with somatuline (somatostatin analogue) and then with oral capecitabine and temozolomide regimen. The patient presented with life-threatening severe hypoglycaemia requiring continuous glucose infusion. We initiated treatment with peptide receptor radionuclide therapy (PRRT) with the radiolabelled somatostatin analogue Lutetium-177-DOTA0-Tyr3. PRRT treatment is associated with inhibition of insulin release and an anti-proliferative and tumour stabilising effect. The patient received four cycles during one year, with the last cycle administered two years ago. At the time of writing, the patient is in complete clinical and radiological remission.